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For some items, SetPromotionalSaleListings call fails with the following error message:
ShortMessage: Invalid PromotionalSale item(s)
LongMessage: Item(s) does not belongs to this user or may not exists
The items belong to the seller and they do exist. So why am I getting this error?
If it is a Mature Audiences item, you will get the error since the Markdown Manager functionality is not support for the Adult Only categories.
As of the time of writing this article, the following stores functionality is not supported for Adult Only categories:
Putting Items on sale
Adult Only category policy